October in Rapid City averages a daily high of 15.4°C with nights around 3.6°C. Expect roughly 7.5 wet days totalling 37.7mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Rapid City is September.
Based on RAPID CITY WEATHER FORECAST OFFICE, SD US (1.8km), 1995–2024. 29 years of October data.